As a technique of measuring a three-dimensional geometry of an object to be measured, a three-dimensional (3D) geometry measuring machine that measures the geometry of the object to be measured by capturing the object to be measured onto which light with a plurality of projection patterns is projected is known (refer to Non-Patent Document, “Saishin Hikari Sanjigen Sokutei” FIG. 4.26, page 47, by Toni Yoshizawa, 2006).
A measured image, acquired by the three-dimensional (3D) geometry measuring machine capturing the object to be measured, may be affected by a surrounding environment such as fluctuations of the amount of light in the surroundings of the object to be measured, fluctuations of luminance of the light projected onto the object to be measured, or the like.
There has been a concern that measurement accuracy at the time of measuring the object to be measured may be negatively influenced if the measured image is affected by the surrounding environment.
This invention focuses on this point, and an object of the invention is to provide a technique for reducing the influence of the surrounding environment on the measured image.